Can you open the project? Which version?
If you can open the project, save as .xml file type, close the file then
re-open the xml file and save as .mpp
If you can't open the file, then there isn't a way I know of, so you may
need to get Microsoft Consulting Services involved. They can recover data,
but it won't be cheap!
If you have the file saved in 2003 format, you could try using the 2003
oledb driver in VBA to read data from the .mpp file. It may get some, but
not all. I can try that for you, but it would take some time to rebuild a
project file with the data (but much cheaper than MSCS!!). Earlier oledb
drivers for earlier versions of Project didn't get all data, but may get
some.
--
Rod Gill
Microsoft MVP for Project
Author of the only book on Project VBA, see:
http://www.projectvbabook.com